A quantum bit reading optimization method, system, device and medium

Abstract

The present invention belongs to the field of computer quantum computing, and specifically relates to a quantum bit reading optimization method, system, device and readable storage medium. The method includes: adjusting the microwave source frequency of the reading cavity within a predetermined frequency range; determining the optimal microwave source frequency point within the predetermined frequency range based on the resonance value of the resonator of the reading cavity at the microwave source frequency adjusted within the predetermined frequency range; and using the frequency point of the optimal microwave source frequency as the working frequency of the reading cavity. Through a quantum bit reading optimization method proposed by the present invention, the microwave source frequency of the reading cavity is fine-tuned, and the optimal microwave source frequency point is determined by the resonance value of the resonator in the reading cavity at different microwave source frequencies. The accuracy of the reading cavity quantum bit after two amplifications at room temperature can be effectively improved.

Description

Technical Field

[0001] The present invention belongs to the field of computer quantum computing, and specifically relates to a quantum bit reading optimization method, system, device and readable storage medium. Background Art

[0002] Quantum computers have shown the ability to surpass classical computers in dealing with some complex problems, such as chemical molecular potential analysis, material science, and large number decomposition problems. This ability is mainly reflected in the great reduction in resource consumption and time. We are now entering the era of medium-scale quantum devices (the chips based on superconducting quantum computing mainly contain hundreds of bits), so we can do some simple algorithm demonstrations and quantum simulations on this platform. Since superconducting quantum bits have good integration advantages with traditional semiconductor processes, they have become the main implementation platform. However, its decoherence time and expansion still have disadvantages, so it is very important to improve the reading of superconducting quantum bits on the existing basis.

[0003] At present, non-destructive measurement is mainly used for reading quantum states. Such measurement requires that the energy we input to read is close to the single-photon level, so we need to amplify the output signal at several levels to obtain a resolvable result. Generally, we place a parametric amplifier at the lowest temperature, place a HEMT at 4K temperature for the second amplification, and finally amplify it twice at room temperature. Since there is no low-temperature parametric amplifier in the laboratory, the signal reading contrast is poor, making it difficult to obtain bit information well.

[0004] Therefore, an effective solution is urgently needed to solve the above problems. Summary of the invention

[0005] In order to solve the above problems, the present invention proposes a quantum bit reading optimization method, comprising:

[0006] adjusting the frequency of the microwave source of the reading cavity within a predetermined frequency range;

[0007] Determine the frequency point of the optimal microwave source frequency within the predetermined frequency range based on obtaining the resonance value of the resonator of the reading cavity at the microwave source frequency adjusted within the predetermined frequency range;

[0008] The frequency point of the optimal microwave source frequency is used as the working frequency of the reading cavity.

[0009] In some embodiments of the present invention, adjusting the microwave source frequency of the reading cavity within a predetermined frequency range comprises:

[0010] determining an initial frequency of the reading cavity, and generating frequencies of a plurality of microwave sources within a predetermined frequency range based on the initial frequency;

[0011] In some embodiments of the present invention, determining the frequency point of the optimal microwave source frequency within the predetermined frequency range based on obtaining the resonance value of the resonator of the reading cavity at the microwave source frequency adjusted within the predetermined frequency range comprises:

[0012] Obtaining resonance values ​​of a resonator of a reading cavity at multiple microwave source frequencies;

[0013] The plurality of resonance values ​​are sorted, and the microwave source frequency corresponding to the largest resonance value is used as the optimal microwave source frequency.

[0014] In some embodiments of the present invention, generating the frequencies of a plurality of microwave sources within a predetermined frequency range based on the initial frequency comprises:

[0015] A plurality of microwave source frequencies are generated for a step size according to the accuracy of the microwave source within a predetermined frequency range.

[0016] Another aspect of the present invention further provides a quantum bit reading optimization system, comprising:

[0017] a frequency adjustment module, the frequency adjustment module being configured to adjust the microwave source frequency of the reading cavity within a predetermined frequency range;

[0018] A frequency optimization module, the frequency optimization module being configured to determine a frequency point of an optimal microwave source frequency within the predetermined frequency range based on a resonance value of a resonator of the reading cavity obtained at the microwave source frequency adjusted within the predetermined frequency range;

[0019] A frequency setting module is configured to use the frequency point of the optimal microwave source frequency as the working frequency of the reading cavity.

[0020] In some embodiments of the present invention, the frequency adjustment module is further configured to:

[0021] determining an initial frequency of the reading cavity, and generating frequencies of a plurality of microwave sources within a predetermined frequency range based on the initial frequency;

[0022] In some embodiments of the present invention, the frequency optimization module is further configured to:

[0023] Obtaining resonance values ​​of a resonator of a reading cavity at multiple microwave source frequencies;

[0024] The plurality of resonance values ​​are sorted, and the microwave source frequency corresponding to the largest resonance value is used as the optimal microwave source frequency.

[0025] In some embodiments of the present invention, the frequency adjustment module is further configured to:

[0026] A plurality of microwave source frequencies are generated for a step size according to the accuracy of the microwave source within a predetermined frequency range.

[0027] Another aspect of the present invention further provides a computer device, comprising:

[0028] at least one processor; and

[0029] A memory, wherein the memory stores computer instructions that can be executed on the processor, and when the instructions are executed by the processor, the steps of the method described in any one of the above-mentioned embodiments are implemented.

[0030] Another aspect of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of any one of the methods described in the above-mentioned embodiments are implemented.

[0031] Through the quantum bit reading optimization method proposed by the present invention, the microwave source frequency of the reading cavity is fine-tuned, and the optimal microwave source frequency point is determined by reading the resonance value of the resonator in the cavity at different microwave source frequencies. The accuracy of the reading cavity quantum bit after two amplifications at room temperature can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 A schematic diagram of a flow chart of a quantum bit reading optimization method provided by an embodiment of the present invention;

[0034] Figure 2 A schematic diagram of the structure of a quantum bit reading optimization system provided by an embodiment of the present invention;

[0035] Figure 3 A schematic diagram of the structure of a computer device provided by an embodiment of the present invention;

[0036] Figure 4 A schematic diagram of the structure of a computer-readable storage medium provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0037] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0038] The present invention aims to solve the problem of reading quantum bit information in existing quantum computers. Currently, non-destructive measurement is mainly used for reading quantum states. Such measurement requires that the energy we input for reading is close to the single-photon level, so the output signal needs multiple levels of amplification to obtain a resolvable result. That is, in the traditional implementation method, a parametric amplifier is usually placed at the lowest temperature, and a HEMT is placed at a temperature of 4K Celsius for a second amplification, and finally amplified twice at room temperature. However, since there is no low-temperature parametric amplifier in the laboratory, the signal reading contrast is poor, so sometimes there is a problem of inaccurate quantum state reading, resulting in abnormal output data of the quantum computer.

[0039] like Figure 1 As shown, in order to solve the above problems, the present invention proposes a quantum bit reading optimization method, comprising:

[0040] Step S1, adjusting the microwave source frequency of the reading cavity within a predetermined frequency range;

[0041] Step S2, determining the frequency point of the optimal microwave source frequency within the predetermined frequency range based on the resonance value of the resonator of the reading cavity obtained at the microwave source frequency adjusted within the predetermined frequency range;

[0042] Step S3: Using the optimal microwave source frequency as the working frequency of the reading cavity.

[0043] In some embodiments of the present invention, adjusting the microwave source frequency of the reading cavity within a predetermined frequency range comprises:

[0044] determining an initial frequency of the reading cavity, and generating frequencies of a plurality of microwave sources within a predetermined frequency range based on the initial frequency;

[0045] In some embodiments of the present invention, determining the frequency point of the optimal microwave source frequency within the predetermined frequency range based on obtaining the resonance value of the resonator of the reading cavity at the microwave source frequency adjusted within the predetermined frequency range comprises:

[0046] Obtaining resonance values ​​of a resonator of a reading cavity at multiple microwave source frequencies;

[0047] The plurality of resonance values ​​are sorted, and the microwave source frequency corresponding to the largest resonance value is used as the optimal microwave source frequency.

[0048] In some embodiments of the present invention, generating the frequencies of a plurality of microwave sources within a predetermined frequency range based on the initial frequency comprises:

[0049] A plurality of microwave source frequencies are generated for a step size according to the accuracy of the microwave source within a predetermined frequency range.

[0050] In an embodiment of the present invention, the range of 5Mhz of the microwave source frequency is used as the control range of the microwave source, and the corresponding adjustment frequencies are output one by one according to the control accuracy of the microwave source device. Assuming that the control accuracy supported by the microwave source device is at least 100hz, that is, each time the microwave frequency output by the microwave source is increased or decreased, it changes by at least 100hz, then a microwave frequency is generated every 100hz in the interval of 2.5Mhz above and below the initial frequency range, and assuming that the initial microwave frequency is 10MHz, 100 frequency points are selected between 7.5Mhz and 12.5MHz, and then the output corresponding frequency of the microwave source device is controlled to the reading cavity according to these 100 frequency points, and the resonance characteristics of the resonator in the reading cavity are obtained, that is, the absorption power of the resonator to the corresponding frequency, and the greater the absorption power, the better the resonance between the resonator and the corresponding frequency. The corresponding frequency can be used as the optimal frequency point for the subsequent microwave source frequency point based on the device.

[0051] In addition, the initial frequency that can cause the resonator to resonate is determined by the absorbed power of the resonator.

[0052] Example:

[0053] The information of the superconducting quantum bit needs to be read out through a reading cavity in the experiment. However, since the reading cavity with poor performance may be produced during the sample processing, in order to improve the contrast of information reading, we can optimize the readout channel to meet the needs of the experiment. First, we determine the approximate position of the reading cavity, and then we obtain the optimal frequency and power points of the reading signal within a frequency range of about 5MHz and a variable power range. In order to achieve the best results as much as possible, we need to make the step size of the variable power range and the step size of the frequency range as small as possible.

[0054] like Figure 2 As shown, another aspect of the present invention further provides a quantum bit reading optimization system, comprising:

[0055] A frequency adjustment module 1, wherein the frequency adjustment module 1 is configured to adjust the microwave source frequency of the reading cavity within a predetermined frequency range;

[0056] A frequency optimization module 2, wherein the frequency optimization module 2 is configured to determine the frequency point of the optimal microwave source frequency within the predetermined frequency range based on the resonance value of the resonator of the reading cavity obtained at the microwave source frequency adjusted within the predetermined frequency range;

[0057] The frequency setting module 3 is configured to use the frequency point of the optimal microwave source frequency as the working frequency of the reading cavity.

[0058] In some embodiments of the present invention, the frequency adjustment module 1 is further configured to:

[0059] determining an initial frequency of the reading cavity, and generating frequencies of a plurality of microwave sources within a predetermined frequency range based on the initial frequency;

[0060] In some embodiments of the present invention, the frequency optimization module 2 is further configured to:

[0061] Obtaining resonance values ​​of a resonator of a reading cavity at multiple microwave source frequencies;

[0062] The plurality of resonance values ​​are sorted, and the microwave source frequency corresponding to the largest resonance value is used as the optimal microwave source frequency.

[0063] In some embodiments of the present invention, the frequency adjustment module 1 is further configured to:

[0064] A plurality of microwave source frequencies are generated for a step size according to the accuracy of the microwave source within a predetermined frequency range.

[0065] like Figure 3 As shown, another aspect of the present invention further provides a computer device, comprising:

[0066] at least one processor 21; and

[0067] A memory 22, wherein the memory 22 stores computer instructions 23 that can be run on the processor 21, and when the instructions 23 are executed by the processor 21, a method for optimizing quantum bit reading is implemented, including:

[0068] adjusting the frequency of the microwave source of the reading cavity within a predetermined frequency range;

[0069] Determine the frequency point of the optimal microwave source frequency within the predetermined frequency range based on obtaining the resonance value of the resonator of the reading cavity at the microwave source frequency adjusted within the predetermined frequency range;

[0070] The frequency point of the optimal microwave source frequency is used as the working frequency of the reading cavity.

[0071] In some embodiments of the present invention, adjusting the microwave source frequency of the reading cavity within a predetermined frequency range comprises:

[0072] determining an initial frequency of the reading cavity, and generating frequencies of a plurality of microwave sources within a predetermined frequency range based on the initial frequency;

[0073] In some embodiments of the present invention, determining the frequency point of the optimal microwave source frequency within the predetermined frequency range based on obtaining the resonance value of the resonator of the reading cavity at the microwave source frequency adjusted within the predetermined frequency range comprises:

[0074] Obtaining resonance values ​​of a resonator of a reading cavity at multiple microwave source frequencies;

[0075] The plurality of resonance values ​​are sorted, and the microwave source frequency corresponding to the largest resonance value is used as the optimal microwave source frequency.

[0076] In some embodiments of the present invention, generating the frequencies of a plurality of microwave sources within a predetermined frequency range based on the initial frequency comprises:

[0077] A plurality of microwave source frequencies are generated for a step size according to the accuracy of the microwave source within a predetermined frequency range.

[0078] like Figure 4 As shown, another aspect of the present invention further provides a computer-readable storage medium 401, wherein the computer-readable storage medium 401 stores a computer program 402, and when the computer program 402 is executed by a processor, a quantum bit reading optimization method is implemented, including:

[0079] adjusting the frequency of the microwave source of the reading cavity within a predetermined frequency range;

[0080] Determine the frequency point of the optimal microwave source frequency within the predetermined frequency range based on obtaining the resonance value of the resonator of the reading cavity at the microwave source frequency adjusted within the predetermined frequency range;

[0081] The frequency point of the optimal microwave source frequency is used as the working frequency of the reading cavity.

[0082] In some embodiments of the present invention, adjusting the microwave source frequency of the reading cavity within a predetermined frequency range comprises:

[0083] determining an initial frequency of the reading cavity, and generating frequencies of a plurality of microwave sources within a predetermined frequency range based on the initial frequency;

[0084] In some embodiments of the present invention, determining the frequency point of the optimal microwave source frequency within the predetermined frequency range based on obtaining the resonance value of the resonator of the reading cavity at the microwave source frequency adjusted within the predetermined frequency range comprises:

[0085] Obtaining resonance values ​​of a resonator of a reading cavity at multiple microwave source frequencies;

[0086] The plurality of resonance values ​​are sorted, and the microwave source frequency corresponding to the largest resonance value is used as the optimal microwave source frequency.

[0087] In some embodiments of the present invention, generating the frequencies of a plurality of microwave sources within a predetermined frequency range based on the initial frequency comprises:

[0088] A plurality of microwave source frequencies are generated for a step size according to the accuracy of the microwave source within a predetermined frequency range.

[0089] Finally, it should be noted that a person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, the storage medium can be a disk, an optical disk, a read-only storage memory (ROM) or a random access memory (RAM), etc. The embodiment of the computer program can achieve the same or similar effect as any of the above-mentioned method embodiments corresponding thereto.

[0090] In addition, typically, the devices and equipment disclosed in the embodiments of the present invention may be various electronic terminal devices, such as mobile phones, personal digital assistants (PDAs), tablet computers (PADs), smart TVs, etc., or large terminal devices, such as servers, etc. Therefore, the protection scope disclosed in the embodiments of the present invention should not be limited to a certain type of device or equipment. The client disclosed in the embodiments of the present invention may be applied to any of the above electronic terminal devices in the form of electronic hardware, computer software, or a combination of the two.

[0091] In addition, the method disclosed in the embodiment of the present invention can also be implemented as a computer program executed by a CPU, and the computer program can be stored in a computer-readable storage medium. When the computer program is executed by the CPU, the above functions defined in the method disclosed in the embodiment of the present invention are performed.

[0092] In addition, the above method steps and system units may also be implemented using a controller and a computer-readable storage medium for storing a computer program that enables the controller to implement the above steps or unit functions.

[0093] In addition, it should be understood that the computer-readable storage medium (e.g., memory) described herein can be a volatile memory or a non-volatile memory, or can include both a volatile memory and a non-volatile memory. As an example and not by way of limitation, a non-volatile memory can include a read-only memory (ROM), a programmable ROM (PROM), an electrically programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), or a flash memory. A volatile memory can include a random access memory (RAM), which can act as an external cache memory. As an example and not by way of limitation, RAM can be obtained in a variety of forms, such as synchronous RAM (DRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), and direct Rambus RAM (DRRAM). The storage devices of the disclosed aspects are intended to include, but are not limited to, these and other suitable types of memory.

[0094] It will also be appreciated by those skilled in the art that various exemplary logic blocks, modules, circuits and algorithm steps described in conjunction with the disclosure herein can be implemented as electronic hardware, computer software or a combination of the two. In order to clearly illustrate this interchangeability of hardware and software, a general description has been given to the functions of various schematic components, blocks, modules, circuits and steps. Whether this function is implemented as software or hardware depends on specific applications and the design constraints imposed on the entire system. Those skilled in the art can implement the described function in various ways for each specific application, but this implementation decision should not be interpreted as causing a departure from the disclosed scope of the embodiments of the present invention.

[0095] The various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure herein may be implemented or executed using the following components designed to perform the functions described herein: a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of these components. A general-purpose processor may be a microprocessor, but alternatively, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP, and / or any other such configuration.

[0096] The step of the method or algorithm described in conjunction with the disclosure here can be directly included in hardware, in a software module executed by a processor, or in a combination of the two. The software module can reside in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, a CD-ROM, or a storage medium of any other form known in the art. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium or write information to the storage medium. In an alternative, the storage medium can be integrated with the processor. The processor and the storage medium can reside in an ASIC. The ASIC can reside in a user terminal. In an alternative, the processor and the storage medium can reside in a user terminal as discrete components.

[0097] In one or more exemplary designs, the functions can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions can be stored on a computer-readable medium or transmitted via a computer-readable medium as one or more instructions or codes. Computer-readable media include computer storage media and communication media, and the communication media include any media that helps to transfer a computer program from one location to another. The storage medium can be any available medium that can be accessed by a general or special-purpose computer. As an example and not limiting, the computer-readable medium can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage devices, disk storage devices or other magnetic storage devices, or can be used to carry or store the required program code in the form of instructions or data structures and can be accessed by a general or special-purpose computer or a general or special-purpose processor. In addition, any connection can be appropriately referred to as a computer-readable medium. For example, if a coaxial cable, optical fiber cable, twisted pair, digital subscriber line (DSL) or wireless technologies such as infrared, radio and microwaves are used to send software from a website, server or other remote source, the above-mentioned coaxial cable, optical fiber cable, twisted pair, DSL or wireless technologies such as infrared, radio and microwaves are all included in the definition of the medium. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk, Blu-ray disc, wherein disks usually reproduce data magnetically, while optical discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

Claims

1. A quantum bit reading optimization method, characterized in that: include: adjusting the frequency of the microwave source of the reading cavity within a predetermined frequency range; Determine the frequency point of the optimal microwave source frequency within the predetermined frequency range based on obtaining the resonance value of the resonator of the reading cavity at the microwave source frequency adjusted within the predetermined frequency range; Using the frequency point of the optimal microwave source frequency as the working frequency of the reading cavity; Among them, the method of determining the frequency point of the optimal microwave source frequency within the predetermined frequency range based on obtaining the resonance value of the resonator of the reading cavity at the microwave source frequency adjusted within the predetermined frequency range includes: obtaining the resonance value of the resonator of the reading cavity at multiple microwave source frequencies; sorting the multiple resonance values, and taking the microwave source frequency corresponding to the largest resonance value as the optimal microwave source.

2. The method according to claim 1, characterized in that: The step of adjusting the microwave source frequency of the reading cavity within a predetermined frequency range comprises: An initial frequency of the reading cavity is determined, and frequencies of a plurality of microwave sources are generated within a predetermined frequency range based on the initial frequency.

3. The method according to claim 2, characterized in that Generating the frequencies of a plurality of microwave sources within a predetermined frequency range based on the initial frequency comprises: A plurality of microwave source frequencies are generated for a step size according to the accuracy of the microwave source within a predetermined frequency range.

4. A quantum bit reading optimization system, characterized in that: include: a frequency adjustment module, the frequency adjustment module being configured to adjust the microwave source frequency of the reading cavity within a predetermined frequency range; A frequency optimization module, the frequency optimization module being configured to determine a frequency point of an optimal microwave source frequency within the predetermined frequency range based on a resonance value of a resonator of the reading cavity obtained at the microwave source frequency adjusted within the predetermined frequency range; A frequency setting module, wherein the frequency setting module is configured to use the frequency point of the optimal microwave source frequency as the working frequency of the reading cavity; The frequency optimization module is further configured to obtain the resonance value of the resonator of the reading cavity under multiple microwave source frequencies; sort the multiple resonance values, and use the microwave source frequency corresponding to the largest resonance value as the optimal microwave source frequency.

5. The system according to claim 4, characterized in that The frequency adjustment module is further configured to: An initial frequency of the reading cavity is determined, and frequencies of a plurality of microwave sources are generated within a predetermined frequency range based on the initial frequency.

6. The system according to claim 5, characterized in that The frequency adjustment module is further configured to: A plurality of microwave source frequencies are generated for a step size according to the accuracy of the microwave source within a predetermined frequency range.

7. A computer device, characterized in that: include: at least one processor; as well as A memory, wherein the memory stores computer instructions executable on the processor, wherein the instructions, when executed by the processor, implement the steps of the method according to any one of claims 1 to 3.

8. A computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the steps of the method according to any one of claims 1 to 3.

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